The present invention concerns a traversing thread guide for winding a thread comprising an elongated cam engaging portion engaging or meshing with an endless helical cam groove of a traverse cylinder, a gliding member connected to the cam engaging portion for guiding the traversing thread guide linearly along an extended guide element and a thread guide member or portion rigidly connected to the gliding member.
A traversing thread guide of the above mentioned type is already known for winding a thread on cross-winders or cross-winding machines, and comprises an elongated cam engaging portion meshing with an endless cam groove extending helically on the outer surface of a traverse cylinder and which groove crosses itself. The gliding member of this traversing thread guide is rotatably connected with the cam engaging portion via a pin rotatably arranged in the gliding member. This pin is offset from the center of the cam engaging portion and is arranged on one end thereof in such manner that the longitudinal axis of the pin extends outside the rotational axis of the traverse cylinder when the cam engaging portion is placed into the cam groove. The gliding member can be supported by guide rims or ledges in correspondingly fitting recesses in parallel arranged guide rails and can be linearly traversed to-and-fro parallel to the rotational axis of the traverse cylinder. On the gliding member a thread guide element is arranged offset with respect to the longitudinal axis of the pin, the thread guide element being designed as an extended guide loop angled away from the gliding member and exceeding the length of the gliding member with its longer part. Owing to the offset arrangement of the gliding member on the pin, the thread guide element can move relative to the center of the cam engaging portion at the reversal points of the linear to-and-fro traversing movement such that a prolonged stop of the thread guide element at the reversal points is avoided, at which reversal points the center of the cam engaging portion temporarily stops.
The common support and linear guiding element for the gliding member however requires expensive manufacturing processes to insure for parallelism of the guide rims and the guide rails as well as of the recesses provided therein, and in which arrangement the parallel guiding action should not be impaired by wear of the material caused by the to-and-fro traversing movement. The rotatable connection between the gliding member and the cam engaging portion is an additional element of the traversing thread guide subject to wear. Thus, the individual guide elements of this type of traversing thread guide not only must be manufactured precisely, but also necessitate a massive and wear resistant design of the cam engaging portion. A traversing thread guide of such complicated design comprising a plurality of wear points, however, is subject to rapid wear by the traversing movement, i.e. it is economically disadvantageous and e.g. unsuitable for high speed applications.
Traversing thread guides are also known to the art wherein a gliding member thereof is guided on the inside surface of a cover- and guide-rail facing a traverse cylinder. On the gliding member there is arranged an extended guide loop, extending in a direction opposite to the direction of rotation of the traversing cylinder away from the gliding member. Since the thread guide member is thus offset from the center of the gliding shoe in such arrangement, as in the arrangement mentioned above, prolonged stopping of the thread guide member at the reversal points is avoided. Traversing thread guides of this type, however, have not proven to be satisfactory, since the gliding member for stability reasons and due to the long extension of the guide loop or bracket must be designed to be massive and wear resistant and contacts the guide rail with a large surface. Due to the massive design the center of gravity of such a traversing thread guide is located within the gliding member which thus is subject to increased wear, something which is disadvantageous at high speeds of the to-and-fro traversing movement.
Also known to the art is the guiding of a traversing thread guide with a cam engaging portion between the bottom of a cam groove and the inside surface of a tube surrounding the traverse cylinder, and which tube is provided with a slot for linearly guiding the gliding member. Together with the guide element for the gliding member this arrangement presents a large number of guide surfaces causing rapid wear of the traversing thread guide, particularly at high operating speeds. Furthermore, guiding the cam engaging portion on both sides in the recesses requires additional manufacturing operations on the inside surface of the tube and necessitates a design of the tube which permits pivoting of a part of the tube to be opened for exchanging the traversing thread guide. A further disadvantage is seen in that due to the arrangement of the thread guide member at the center of the traversing thread guide, the thread guide member is stopped temporarily at the reversal points, which proves disadvantageous for uniform winding.